I really loved this one! It reminded me so much of a lot of flash games I used to love that had this type of progression system. It's that nice tight loop that keeps you hooked trying to incrementally beat your last score until you eventually make it all the way, and I think you managed to nail it. The last run felt so satisfying with how the movement and speed boost mechanics were handled, even when I hit speeds where I could barely tell where the enemies were that I was hitting.
Cute character designs, too. I might say music would've been nice, but I think the clean and satisfying sound effects did a fine job in lieu of it.